Culture

In hotter, dryer conditions with climate change, a secret agent for more sustainable agricultural production could lie in harvesting the diverse beneficial soil microbiome in native bushland settings, scientists say.

New research from CSIRO, Flinders University and La Trobe University highlights the importance of soil biological health and further potential to use organic rather than chemical farm inputs for crop production.

"We know antibiotics are very useful in pharmaceuticals, and actinobacteria found plentifully and in balance in various natural environments play a vital role in the plant world," says lead author Dr Ricardo Araujo, a visiting Flinders University researcher from the University of Porto in Portugal.

"These actinobacterial communities contribute to global carbon cycling by helping to decompose soil nutrients, increase plant productivity, regulate climate support ecosystems - and are found in abundance in warm, dry soil conditions common in Australia."

A new article in Soil Biology and Biochemistry is one of the first dedicated studies of Australian actino-bacterial diversity in different areas of the Southern Hemisphere - using the bacterial gene sequence dataset generated through the 'Biomes of Australian Soil Environments' project with soil samples from across the nation, including mainland, the island state of Tasmania as well as King Island, Christmas Island and the Northern Antarctica for comparative soil profiles.

Other researchers from the La Trobe University AgriBio Centre contributed to the analysis of 2211 actinobacterial operational taxonomic units (OTUs) mapped in mainland Australia, and 490 OTUs from Tasmania, King Island, Christmas Island and Northern Antarctica.

CSIRO Agriculture and Food senior principal research scientist, Associate Professor Gupta Vadakattu, says the dfferences we found between mainland Australia and more remote locations showed how agriculture has had an impact on the diversity of actinobacterial.

"Our study shows how native vegetation is a reservoir for these important soil microorganisms, and this could be used to enrich adjoining agricultural soils," says Associate Professor Vadakattu, adding an intriguing finding was the similarity in actinobacteria profiles of King Island and areas of Antarctica where these continents were once connected.

"Patterns of actinobacteria dispersal suggest only a small fraction of them had the capability of spreading throughout the Southern Hemisphere, especially across oceans."

Flinders University colleague Professor Chris Franco, says biotechnology has long benefited from actinobacteria for human and animal health products, and increasingly in sustainable agriculture.

"The diversity and structure of soil antinobacterial communities are influenced by multiple factors, representing one of the most abundant soil bacterial taxa across a diverse range of ecological regions - from deserts to Antarctica," Professor Franco says.

"There is much more we need to learn about their potential in primary production and retaining and incorporating native plants in our ecosystems."

Various scientific studies have warned of a global decline in the abundance and diversity of insects. These studies have been carried out mainly on the European and North American continents, with other regions, such as islands, have been less studied.

This in mind, an international research team from Portugal, France and Finland studied the insects captured over six years in the native forests of Terceira island, the Azores.

The results revealed that the diversity of exotic species of arthropods increased with time. Exotic species have been introduced into the archipelago consciously or inadvertently through economic activities.

"A greater diversity of exotic species may imply a change in various types of ecosystem services, disrupting processes such as predation and recycling of nutrients," says Paulo Borges, researcher at the at the University of the Azores, Portugal.

In the Azores, exotic species have their maximum abundance and diversity in habitats created by man.

"The fragmentation of native habitats and the proximity of some of these non-native habitats is promoting a flow of exotic species to the native forest. The process seems to be increasing in recent years possibly due to the combination of climate change and degradation of the native forest due to the spread of invasive plants,"explains Pedro Cardoso, curator at the Finnish Museum of Natural History Luomus, University of Helsinki, Finland.

The study also shows a slight decrease in the abundance of island species that are not found anywhere else on the planet, such as the Azorean money spider (Savigniorrhipis acoreensis), which occurs on all the archipelago with the exception of Corvo island.

The study took place between 2013 and 2018. During that time, 30 thousand arthropods were captured in the native forest of Terceira. The insects collected corresponded to 159 species, 32 of which are endemic.

A new guideline aimed at helping clinicians identify the difficult-to-diagnose acute aortic syndrome is published in CMAJ (Canadian Medical Association Journal).

Acute aortic syndrome (AAS) is a life-threatening condition that underlies 1 in 2000 visits to the emergency department for severe chest or back pain. The rate of misdiagnosis is estimated to be as high as 38%, and the risk of death can increase 2% for every hour of delay in diagnosis.

The target audience for the guideline includes emergency physicians, primary care clinicians, internists, radiologists, vascular surgeons, cardiothoracic surgeons and critical care physicians as well as decision-makers and patients.

"This guideline is intended as a resource for practising clinicians, both as an evidence base and a guide to investigation for this high-risk aortic catastrophe," writes Dr. Robert Ohle, an emergency physician at the Health Science North Research Institute, Northern Ontario School of Medicine, Sudbury, Ontario, with coauthors.

Recommendations include:

* Assessment of risk factors, pain features and high-risk physical exam findings to establish pre-test disease risk

o Risk factors include connective tissue disease, aortic valve disease, recent aortic procedure, aortic aneurysm and family history of AAS

o High-risk pain includes sudden-onset or thunderclap pain, severe or worst-ever pain, tearing, migrating or radiating pain

o High-risk physical exam findings include aortic regurgitation, pulse deficit, neurological deficit and hypotension/pericardial effusion

* Diagnostic strategy

o The guideline recommends no investigation of those at low risk, D-dimer testing of people of moderate risk and immediate electrocardiogram-gated computed tomography (CT) of the aorta for high-risk individuals

To help with decision-making, the guideline group created a clinical decision aid to accompany the guideline.

The guideline can be adapted by clinicians based on local circumstances, as a one-size-fits-all approach may not be feasible.

"This document may serve as a basis for adaption by local, regional or national guideline groups," write the authors. "For example, guideline implementation in an urban centre with 24-hour access to CT may differ from a rural or remote location that requires transfer of a patient with accompanying staff."

A school-based vision screening program in kindergarten, shown to be effective at identifying untreated vision problems in 1 in 10 students, could be useful to implement widely in diverse communities, according to new research in CMAJ (Canadian Medical Association Journal).

Vision problems can lead to amblyopia (known as "lazy eye") and potential learning problems.

"These are practical details needed by funders to make decisions about implementing school-based vision screening," writes Dr. Mayu Nishimura, Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, and Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children (SickKids), Toronto, with coauthors.

Researchers offered vision screening to 5884 children in junior and senior kindergarten at 43 schools in 15 Ontario communities from October 2015 to June 2017. Most children participated, and just under half of participants were referred for follow-up eye exams. More than 10% of children (516) who were screened were found to have a visual problem during the follow-up eye exam. For 67% of the children found to have a visual problem, this was their first eye exam. Amblyopia was found in 164 children (3.4%), and 458 (9.5%) children were prescribed glasses.

"These numbers show that the status quo (in 2015-2017) was insufficient in identifying and treating young children with a visual problem before grade 1. The willingness of school boards and principals to participate in our study underlines the recognized need for better access to visual health care for children in kindergarten," write the authors.

Adequate follow-up care, such as visits to eye care professionals, prescriptions for glasses, appointment reminders and information about the importance of treatment, are critical to ensure the success of a vision screening program.

"Feasibility of a school-based vision screening program to detect undiagnosed visual problems in kindergarten children in Ontario" is published July 20, 2020.

The “enhanced paper grip test” validated by researchers from the Centre for Biomechanics and Rehabilitation Technologies (CBRT) at Staffordshire University involves pulling a small card from underneath the participant’s foot while asking them to grip with their big toe (Hallux).

The proposed test can potentially be used to monitor muscle weakness in clinics for better falls-risk assessment in patients with diabetes.

Dr Aoife Healy, Associate Professor of Human Movement Biomechanics at CBRT, said: “The paper grip test is a simple, clinically applicable test to detect muscle weakness in the foot. The current paper builds on our previous work and shows its usefulness in assessing strength and balance in this group of vulnerable patients.”

The experiment involved assessing twenty healthy volunteers at Staffordshire University’s specialist Biomechanics labs and ten people with diabetes at a diabetic foot clinic in India.

Hallux grip force was previously found to be strongly linked to the strength of all muscle groups of the foot and ankle and to the ability to maintain balance. The latest results published in Gait and Posture on a modified test shows the reliability and validity of Hallux grip force during clinical assessment.

Dr Lakshmi Sundar, a co-author in this study and a diabetic foot specialist from Chennai in India, added: “This type of simple clinical assessment is extremely valuable in low resource settings and helps in providing effective clinical advice.”

Dr Panagiotis Chatzistergos, Associate Professor in Orthopaedic and Rehabilitation Biomechanics, who led this study highlighted: “The original version of the paper grip test was shown to be effective in detecting foot muscle-weakening but its outcome is operator-dependent. To overcome this limitation, we have developed this enhanced test that replaces the pass/fail outcome with a continuous measurement of the pulling force that is needed to remove the card.”

This latest study is part of the Centre for Biomechanics and Rehabilitation Technologies’ wider work in the area of diabetic foot management which includes research to help prevent life-threatening foot ulcers and amputations.

Professor Nachi Chockalingam, Director of the Centre for Biomechanics and Rehabilitation Technologies, said: “Falls and fear of falling are a major issue in the management of older adults. Also, falling for the first time sets in motion a cycle of increased fear of falling, reduced activity and loss of strength. This leads to a higher risk for further falls. So, it is important to identify individuals who might fall and preventing the first fall is extremely important.”

Read the full paper, published in Gait and Posture, here - Reliability and validity of an enhanced paper grip test; a simple clinical test for assessing lower limb strength

Journal

Gait & Posture

DOI

10.1016/j.gaitpost.2020.07.011

PITTSBURGH--A robot travelling from point A to point B is more efficient if it understands that point A is the living room couch and point B is a refrigerator, even if it's in an unfamiliar place. That's the common sense idea behind a "semantic" navigation system developed by Carnegie Mellon University and Facebook AI Research (FAIR).

That navigation system, called SemExp, last month won the Habitat ObjectNav Challenge during the virtual Computer Vision and Pattern Recognition conference, edging a team from Samsung Research China. It was the second consecutive first-place finish for the CMU team in the annual challenge.

SemExp, or Goal-Oriented Semantic Exploration, uses machine learning to train a robot to recognize objects -- knowing the difference between a kitchen table and an end table, for instance -- and to understand where in a home such objects are likely to be found. This enables the system to think strategically about how to search for something, said Devendra S. Chaplot, a Ph.D. student in CMU's Machine Learning Department.

"Common sense says that if you're looking for a refrigerator, you'd better go to the kitchen," Chaplot said. Classical robotic navigation systems, by contrast, explore a space by building a map showing obstacles. The robot eventually gets to where it needs to go, but the route can be circuitous.

Previous attempts to use machine learning to train semantic navigation systems have been hampered because they tend to memorize objects and their locations in specific environments. Not only are these environments complex, but the system often has difficulty generalizing what it has learned to different environments.

Chaplot -- working with FAIR's Dhiraj Gandhi, along with Abhinav Gupta, associate professor in the Robotics Institute, and Ruslan Salakhutdinov, professor in the Machine Learning Department -- sidestepped that problem by making SemExp a modular system.

The system uses its semantic insights to determine the best places to look for a specific object, Chaplot said. "Once you decide where to go, you can just use classical planning to get you there."

This modular approach turns out to be efficient in several ways. The learning process can concentrate on relationships between objects and room layouts, rather than also learning route planning. The semantic reasoning determines the most efficient search strategy. Finally, classical navigation planning gets the robot where it needs to go as quickly as possible.

Semantic navigation ultimately will make it easier for people to interact with robots, enabling them to simply tell the robot to fetch an item in a particular place, or give it directions such as "go to the second door on the left."

Asian gypsy moths feed on a wide range of important plants and trees. White pine blister rust can kill young trees in only a couple of years. But it's not always easy to detect the presence of these destructive species just by looking at spots and bumps on a tree, or on the exterior of a cargo ship.

Now a new rapid DNA detection method developed at the University of British Columbia can identify these pests and pathogens in less than two hours, without using complicated processes or chemicals - a substantial time savings compared to the several days it currently takes to send samples to a lab for testing.

"Sometimes, a spot is just a spot," explains forestry professor Richard Hamelin, who designed the system with collaborators from UBC, Natural Resources Canada and the Canadian Food Inspection Agency. "Other times, it's a deadly fungus or an exotic bug that has hitched a ride on a shipping container and has the potential to decimate local parks, forests and farms. So you want to know as soon as possible what you're looking at, so that you can collect more samples to assess the extent of the invasion or begin to formulate a plan of action."

Hamelin's research focuses on using genomics to design better detection and monitoring methods for invasive pests and pathogens that threaten forests. For almost 25 years, he's been looking for a fast, accurate, inexpensive DNA test that can be performed even in places, like forests, without fast Internet or steady power supply.

He may have found it. The method, demonstrated in a preview last year for forestry policymakers in Ottawa, is straightforward. Tiny samples like parts of leaves or branches, or insect parts like wings and antennae, are dropped into a tube and popped into a small, battery-powered device (the Franklin thermo cycler, made by Philadelphia-based Biomeme). The device checks to see if these DNA fragments match the genomic material of the target species and generates a signal that can be visualized on a paired smartphone.

"With this system, we can tell with nearly 100 per cent accuracy if it is a match or not, if we're looking at a threatening invasive species or one that's benign," said Hamelin. "We can analyze up to nine samples from the same or different species at a time, and it's all lightweight enough--the thermocycler weighs only 1.3 kilos--to fit into your backpack with room to spare."

The method relies on PCR testing, the method that is currently also the gold standard for COVID-19. PCR testing effectively analyzes even tiny amounts of DNA by amplifying (through applying heating and cooling cycles) a portion of the genetic material to a level where it can be detected.

Hamelin's research was supported by Genome Canada, Genome BC and Genome Quebec and published in PLOS One. The UBC team, including lead author Arnaud Capron, tested this approach on species such as the Asian gypsy moth, white pine blister rust and sudden oak death pathogen, which are listed among the most destructive invasive pests worldwide.

"Our forestry, agriculture and horticulture are vital industries contributing billions of dollars to Canada's economy so it's essential that we protect them from their enemies," added Hamelin. "With early detection and steady surveillance, we can ensure that potential problems are nipped, so to speak, in the bud."

Cellular signal transmission is not only optimized for precision - it also includes a cost cap. The relationship between information and energy, a concept well established in physics and engineering, is likely to fundamentally shape cellular signalling networks. One of the questions addressed by researchers at the Max Planck Institute for Terrestrial Microbiology, headed by biophysicist Victor Sourjik, is: What enables reliable transmission of signals in the "noisy" cellular environment? The research team is studying signal transmission in baker's yeast (Saccharomyces cerevisiae), combining information theoretical approaches with quantitative experiments.

Precise signaling is crucial for the fitness of every living organism: whether during development or while communicating with a possible mating partner, only accurate transmission of received signals enables cells to trigger appropriate responses. In biological systems, random fluctuations of signals always lead to background noise, which can impede cell communication. Organisms must therefore have developed strategies to improve the accuracy of signal transmission in the presence of such interference. However, little is yet known about how noise suppression is achieved in cellular networks.

The pheromone signalling pathway of baker's yeast belongs to a class of MAPK (mitogen-activated protein kinase) signalling pathways, which in eukaryotes commonly play a key role in the transmission and translation of extracellular stimuli into intracellular responses such as cell differentiation, proliferation or stress responses.

That the pheromone signalling pathway of yeast contains negative feedback regulations could be seen as clear indication of selection for increased accuracy. Surprisingly, however, both theoretical and experimental analyses of the signalling pathway showed that its accuracy could be easily further improved by increasing the sensitivity of one of the negative feedbacks. So why this discrepancy between the potentially more efficient hypothetical and the natural design? In other words, why didn't yeast naturally optimize the system this way?

Costs versus benefits

The answer seems to lie in the cellular economics. The discrepancy disappears when the energy investment in the operation of the signalling pathway is also considered. "We were able to show that the core of the MAPK signalling pathway, the phosphorylation cycle, has measurable fitness costs. When these are taken into account, and the accuracy of the signal transduction is weighed against the energetic costs of the signalling pathway operation, the naturally observed design appears optimal," explains Alexander Anders, first author of the current publication.

"Here we observe a relation between information and energy, analogous to what is well established in physics and engineering sciences." says Victor Sourjik. "In biology, little attention has been paid to this interplay so far. Our work suggests that cost-benefit trade-off in information transfer must have been important in the evolution of cellular signalling systems. This helps us to better understand the evolutionary optimization of cellular signalling networks." How biology has solved this fundamental dilemma of information costs in other cases remains to be elucidated.

Scientists and historians working at McMaster University, the Mütter Museum and the University of Sydney have pieced together the genomes of old viruses that were used as vaccination strains during and after the American Civil War ultimately leading to the eradication of smallpox.

Smallpox was one of the most devastating viral diseases ever to strike humankind, killing about three out of every 10 people who were infected. Those who survived were frequently disabled, blind or disfigured.

The World Health Organization recently celebrated the 40th anniversary of the eradication of smallpox, the most successful campaign ever attempted. As researchers around the world work feverishly to develop a vaccine against COVID-19, the success of the campaign and the findings of this paper, outlined the journal Genome Biology, point to the value of vaccination, say researchers. They suggest other vaccines are waiting to be discovered among the viral relatives of today's influenza and coronaviruses.

"Understanding the history, the evolution and the ways in which these viruses can function as vaccines is hugely important in contemporary times," says evolutionary geneticist Hendrik Poinar, who is director of the McMaster Ancient DNA Centre, where the work was done, and a principal investigator at the university's Michael G. DeGroote Institute for Infectious Disease Research.

"This work points to the importance of looking at the diversity of these vaccine strains found out in the wild. We don't know how many could provide cross protection from a wide range of viruses, such as flus or coronaviruses," he says.

The concept of widespread vaccination dates back to 1796, when English physician Edward Jenner, known for his remarkable contributions to medicine, observed that exposure to a milder illness (called cowpox) thought to be transferred from cows with a similar pox-like illness on their udders to milkmaids, offered protection against future smallpox outbreaks. However, the method and source material used for early smallpox vaccinations remained unstandardized for over a century. While "cowpox" is often referenced as the source of the first vaccination, little had been known about the specific origins and diversity of the virus strains used in early smallpox vaccination programs

For their study, researchers used sophisticated techniques developed at the McMaster Ancient DNA Centre to reconstruct and analyse the genomes of virus fragments recovered from vaccination kits used during the Civil War era.

The kits, part of a medical collection at the Mütter Museum of the College of Physicians of Philadelphia, contained lancets and small glass plates for mixing fluid for vaccines that had been collected from blisters of deliberately infected subjects, and tin boxes with sliding lids to contain scab material.

The techniques used in this paper resulted in the successful recovery of viral molecules from both organic sources, such as scab material, but also from the non-destructive sampling of inorganic materials, such as tin boxes and glass slides, that contained no evidence of organic residues.

This finding opens a new possible field of study into medical history through the non-destructive examination of materials previously associated with biological samples.

The researchers were able to determine that in the 1860s and 1870s, medical practitioners in Philadelphia were using a vaccinia virus strain that was still being propagated in human subjects. The milder relative of the deadly smallpox pathogen was introduced into the body, usually by applying pus or scabs to a scratch or cut in the skin, where it helped recipients develop immunity to smallpox.

An overriding concern about vaccine design is how close - from an evolutionary standpoint- the vaccine strain must be to the one causing disease in order to prevent illness. Here, the vaccinia strains used for vaccination are in fact very distantly related to the virus that causes smallpox. The slow mutation rate of orthopox viruses (of which both vaccinia and variola are members) likely allows for this 'distant' protection.

"Vaccination is a wonderful process with a rich medical history that we should celebrate," says Ana Duggan, a former postdoc in the Department of Anthropology at McMaster, now at the Public Health Agency of Canada, who was lead researcher on the study. "Medical museums are incredible repositories of our past and of our collective history. The new tools we develop in this work allow us to begin to investigate how medical sources, procedures and techniques have changed through time."

Toshinori Chiba (ATR) and his collaborators have proposed an innovative new "Reciprocal Inhibition Model" of post-traumatic stress disorder (PTSD), which may aid considerably in its treatment. This model comprehensively explains the inhomogeneous nature of PTSD by addressing inter- and intra-patient variabilities at the neural, attentional, and symptom levels. This model may therefore pave the way for individual-tailored clinical PTSD treatment.

In the current climate where COVID-19 is pervasive, this new model of PTSD may be particularly pertinent. This is because patients recovering from COVID-19 are beginning to display "PTSD-like" adverse psychological effects related to fear and anxiety. Some example patients who have recovered from COVID-19, such as Stuart Gannaway (pseudonym), age 20, report symptoms such as increased fearfulness and mentally re-living their time in hospital over and over again. Others, such as Anabelle Hendy (pseudonym), age 34, report a different subset of psychological symptoms. Anabelle reflects "(after my COVID-19 diagnosis) I don't feel like myself anymore... I kind of feel like there is a veil between myself and reality, if that makes sense? I keep zoning out. I avoid talking about corona with people from work- I am worried they would be scared of me if they found out I had it, even though I am recovered now". A comprehensive explanation of why, after trauma, different patients develop different psychological symptoms is provided by the new "Reciprocal Inhibition Model". The proposals of this model pave the way for novel individual-specific clinical treatments. This model may therefore be of particular use under the current circumstances, where the number of physically-recovered yet mentally-still-traumatized Covid19 patients is increasing.

In movies, patients with PTSD are commonly portrayed as people who remain on high alert for threat and who often mentally re-live past traumatic events (similar to the symptoms reported by Stuart, above). While this is often true, paradoxically some patients with PTSD do their best to avoid threat and its associated memories, resulting in a dissociation from reality and a numbing of their emotions (similar to the symptoms reported by Anabelle, above). In line with these two clusters of symptoms, current clinical diagnostic criteria divide patients into two PTSD subtypes. However, the newly proposed "Reciprocal Inhibition Model" submits that differences between patients with PTSD may not be this black and white, but instead span the whole range of grey in between. It further proposes something not taken into account under current diagnostic criteria- that differences likely occur within individual patients so that each individual does not always consistently experience the same symptoms, but can switch between different states with different symptoms. Indeed, when the two recovered COVID-19 patients described above were further questioned, Stuart confides that he does sometimes find himself "zoning out" and Anabelle admits that she does sometimes find herself replaying her "darkest times with corona", indicating that these patients do sometimes switch between different subsets of symptoms.

What does "reciprocal inhibition" mean? To comprehend this, imagine two children fighting for your attention- each tries to cover the mouth of the other so that only the child who is currently winning can be heard clearly at any given time. This is similar to what happens in the brain during "reciprocal inhibition", where two neural regions alternate between dominating each other. The newly proposed model is called the "Reciprocal Inhibition Model" of PTSD, because, in this model, reciprocal inhibition between two distinct regions of the brain- the amygdala and the ventrolateral prefrontal cortex- is proposed to be what causes individual patients to switch between different states with different symptoms.

The "Reciprocal Inhibition Model" of PTSD predicts that when participants are in an amygdala dominant state, their attention will be biased towards threat causing them to experience relatively more fear-related symptoms, such as increased mental re-living of past traumatic events. Recovered COVID-19 patients, who display these kind of symptoms (such as Stuart, reported above), may be overly spending time in this state. On the other hand, when participants are in a ventrolateral prefrontal cortex dominant state, their attention will be biased away threat causing them to experience relatively more avoidance-related symptoms, such as a dissociation from reality and emotional numbing. Recovered COVID-19 patients who display these kind of symptoms (such as Anabelle, described above) may be overly spending time in this state. This model supposes that PTSD subtype diagnoses, that are still being used in the clinic today, might reflect categorical judgements based on the ratio of time that patients spend in each of these states.

In the paper which proposes the Reciprocal Inhibition Model of PTSD, experimental evidence is provided that supports the idea that attention alternates- even within the same individual patient- so that sometimes it is biased towards and sometimes it is biased away from threat. Furthermore, experimental and meta-analysis evidence is provided that supports the predicted relationship between attention and symptoms, and the predicted relationship between amygdala activity and symptoms. Other aspects of this model still need to be tested directly, but are well supported by existing literature.

If individual patients do alternate between states, as predicted in this model, then this has big implications for individual-tailored clinical treatments of PTSD. This is because different clinical treatments for PTSD have been shown to be more or less effective dependent on the amygdala reactivity of the patient (e.g. exposure therapy is less effective when amygdala reactivity is high). Until now, clinicians may have selected treatments for an individual patient with PTSD based on their diagnosed subtype (e.g. amygdala reactivity is thought to be exaggerated in the non-dissociative subtype, so people with this subtype might be less likely to be prescribed exposure therapy). However, if the predictions of the Reciprocal Inhibition Model are true, then this means that different treatments might be more or less effective for the same individual patient with PTSD depending on the state that they are currently in. This may also apply to patients experiencing emotional distress after COVID-19. Quick measurement of the patient's current state (symptoms could be used as a proxy) might inform clinicians of the most appropriate treatment for an individual patient during any given therapy session.

The Reciprocal Inhibition Model of PTSD includes novel proposals about the neural mechanisms that underlie PTSD. Elucidation of such mechanisms is vital if, for the treatment of PTSD, one wishes to use methods such as neurofeedback (where certain regions of the brain, or the way that certain regions of the brain work together, are "retrained") or transcranial magnetic stimulation (where, essentially, magnets are used to induce or decrease activity in targeted regions of the brain). Cutting-edge research is showing much benefit from these kinds of treatments and so further studies to confirm the neural mechanistic proposals of this model are imperative.

Cambridge scientists have developed a new way to fortify shellfish to tackle human nutrient deficiencies which cause severe health problems across the world. The team is now working with major seafood manufacturers to further test their microencapsulation technology, or "Vitamin Bullets".

** A proof of the paper can be downloaded here: https://www.dropbox.com/s/pqmez3rzutbhk55/Willer%20et%20al%20Author%27s%20Proof%2029062020.pdf?dl=0 **

Over two billion people worldwide are nutrient deficient, leading to a wide range of serious health problems. Fortifying food with micronutrients is already an industry standard for enhancing public health but now scientists at Cambridge's Department of Zoology have teamed up with Cambridge-based company BioBullets to supercharge one of the world's most healthy and sustainable sources of animal protein: bivalve shellfish such as oysters, clams and mussels.

Dr David Aldridge and PhD student David Willer have produced the world's first microcapsule specially designed to deliver nutrients to bivalves which are beneficial to human health. These "Vitamin Bullets" - manufactured under patent by Aldridge's company, BioBullets - are tailored for optimal size, shape, buoyancy and to appeal to shellfish.

This breakthrough, described in a study published today in the journal 'Frontiers in Nutrition', is particularly valuable because when we eat bivalves, we consume the entire organism including its gut, meaning that we digest the nutrients which the animals consumed towards the end of their lives. This makes bivalve shellfish the ideal target for nutritional fortification.

In their Cambridge laboratory, the scientists trialled Vitamin A and D fortified microcapsules on over 100 oysters to identify the optimal dose. They also established that this should be fed for 8 hours towards the end of "depuration", the period in which bivalves are held in cleansing tanks after being harvested.

The team found that fortified oysters delivered around 100 times more Vitamin A, and over 150 times more Vitamin D, than natural oysters. Even more importantly, they dramatically outperformed salmon, one of the best natural sources of these vitamins. The fortified oysters provided more than 26 times more Vitamin A and over 4 times more Vitamin D than salmon. The scientists found that a serving of just two of their supercharged shellfish provided enough Vitamin A and D to meet human Recommended Dietary Allowance (RDAs).

Vitamin A and D deficiencies pose a particularly serious public health challenge - in Ghana more than 76% of children are Vitamin A deficient, causing widespread mortality and blindness. In India, 85% of the population is Vitamin D deficient, which causes cardiovascular diseases, osteoporosis, and rickets. Even in the US, over 40% of people are Vitamin D deficient.

David Willer said: "We have demonstrated a cheap and effective way to get micronutrients into a sustainable and delicious source of protein. Targeted use of this technology in regions worst affected by nutrient deficiencies, using carefully selected bivalve species and micronutrients, could help improve the health of millions, while also reducing the harm that meat production is doing to the environment".

David Aldridge said: "We are very excited about BioBullets' potential. We are now establishing links with some of the world's biggest seafood manufacturers to drive a step change in the sustainability and nutritional value of the seafood that we consume."

Bivalves have a higher protein content than beef, are a rich source of omega-3 fatty acids, and have some of the highest levels of key minerals of all animal foods. Nevertheless, the nutrients that they deliver naturally is unlikely to solve global deficiencies. These shellfish are also highly sustainable to farm, having a far lower environmental footprint than animal meat or fish, and lower even than many plant crops such as wheat, soya, and rice.

Bivalves are a highly affordable food source when produced at large scale and the global market is rapidly expanding. Production in China alone has grown 1000-fold since 1980 and there is great potential to sustainably expand bivalve aquaculture worldwide, with over 1,500,000 km2 available for sustainable low-cost industry development, particularly around the west coast of Africa and India.

The researchers point out that consumers in poorer regions where vitamin deficiencies are most prevalent are more likely to buy slightly more expensive fortified food than to make additional purchases to take supplement pills. They calculate that fortification adds just $0.0056 to the cost of producing a single oyster.

You have been diagnosed with prostate cancer and your doctor gives you the option of not being treated, but of remaining under observation: is there any objective way you can decide to be treated or not treated? What should you do? Now using first results from analysis of the world's biggest Active Surveillance prostate cancer database, the GAP3 consortium* has begun to identify which patients are at risk of the disease developing and which patients can continue to safely delay treatment. This work is presented at the virtual European Association of Urology congress.

As lead researcher, Dr Mieke Van Hemelrijck (King's College London) says: "Current methods of deciding whether or not to recommend treatment are not reliable. Our analysis shows that we should be able to produce a single global methodology, which will give accurate estimates on how aggressive these cancers are. These will feed directly into the treatment decision, and give men the reassurance they need to decide on treatment".

Prostate cancer is one of the leading causes of death in men, but many men who discover they have prostate cancer are not in any immediate danger: they have Low Risk Prostate Cancer. Over the past 10 years, an increasing number of these men have been given the option of going on active surveillance, rather than being immediately treated. Active surveillance means that men continue to be monitored and tested (via PSA levels, biopsy, and other tests), with treatment only starting when the cancer shows signs of developing. The number of men on active surveillance varies from country to country, with up to 80% of men delaying treatment in some countries. However, there are no generally accepted ways of understanding who is at risk, and as many as 38% of men who start active surveillance drop out within 5 years.

Van Hemelrijck said: "Prostate cancer treatment can have significant side-effects such as erectile dysfunction and incontinence, so often avoiding intrusive surgery or radiotherapy can benefit the patient. Nevertheless, being told you have cancer puts great psychological pressure on men to agree to treatment, so understanding just how aggressive the cancer is before deciding on treatment is essential. At the moment we just don't have that reassurance".

Although active surveillance is considered a real step forward in management of low risk prostate cancer, there is surprisingly little agreement on which men will benefit. Doctors consider a range of factors, such as age, PSA score, biopsy details, technical details of the cancer, and so on. But the decision on whether or not to start treatment is still often subjective. Erasmus MC , department of Urology was tasked by Movember to coordinate the development of a global database on Active Surveillance (the GAP3 consortium). Dr Van Hemelrijck worked with a team of researchers from the GAP3 Consortium to develop the world's most accurate active surveillance nomogram.

A nomogram is a treatment calculator, similar to an App: you feed in the details and it gives you advice on whether or not to treat. Local nomograms exist, but a global version is needed to be generally applicable. Working with data from the 14,380 patients on the Movember database (the world's largest), they were able to input data such as age, size and condition of the tumour, PSA, biopsy details, time on active surveillance, genetic factors, etc.

"Not surprisingly, we have found that even accounting for these factors there was still differences in outcomes between participating centres. But this work has shown that it will be possible to produce a nomogram which can guide treatment. Just as importantly, the work shows which additional factors need to be included in the nomogram in future to enable us to eliminate this variation and produce accurate estimates of tumour aggressiveness".

Commenting, EAU Adjunct Secretary General Professor Hendrik Van Poppel (University of Leuven, Belgium ) said;

"This work shows that it should be possible to develop a global nomogram - in other words, a system which allows us to predict whether active surveillance will be suitable for individual low and intermediate risk prostate cancer patients. This would be an important step forward in terms of the reassurance we can offer patients, and in choosing treatment pathways. The urology community would welcome this, and will be happy to cooperate in taking this project forward".

This is an independent comment; Professor Van Poppel was not involved in this work.

The health benefits of maintaining routine childhood vaccination programmes in Africa during the COVID-19 pandemic far outweigh the risk of SARS-CoV-2 transmission that might be associated with clinic visits, according to a modelling study published in The Lancet Global Health journal.

For every additional COVID-19 death that might be associated with additional exposure to the virus during routine clinic visits, the model predicts that 84 deaths in children before five years of age (uncertainty interval 14-267 [1]) could be prevented by continuing with routine vaccinations. The additional risk of COVID-19 transmission associated with clinic visits is predicted to primarily affect older adults living in the same household as the vaccinated children.

The findings suggest that continuing with usual vaccination schedules could prevent 702,000 child deaths (uncertainty interval 635,000-782,000) from the point of immunisation until they reach five years of age.

The study looked at all 54 countries of Africa and found that in all countries, the number of child deaths averted through vaccination far exceeded the number of excess COVID-19 deaths that might be associated with clinic visits.

However, the authors acknowledge there are other issues that will affect whether vaccination programmes can continue, such as vaccine supply chain problems or healthcare staff shortages during the pandemic.

Dr Kaja Abbas, joint lead author of the study, from the London School of Hygiene and Tropical Medicine, UK, said: "We found that, even with our most conservative estimates, the benefits of routine childhood immunisation in Africa are likely to far outweigh the risk of additional COVID-19 transmission that might ensue, and these programmes should be prioritised as far as logistically possible." [2]

National immunisation programmes are at risk of disruption due to the severe health system constraints associated with the ongoing COVID-19 pandemic and physical distancing measures introduced to mitigate transmission of the virus.

Researchers created a mathematical model to assess the risks and benefits of continuing with vaccination programmes during the current pandemic for all 54 countries of Africa. Their model assumes that the spread of COVID-19 in African countries will be similar to other countries that were affected earlier in the pandemic and were unable to control the virus. It assumes around 60% of the population will become infected and that the potential disruption to health services will last for six months.

Exact data on the risk of SARS-CoV-2 infection associated with routine clinic trips for childhood immunisations were not available, so the model was based on assumptions relating to the likely number of people encountered during such a journey, both at the clinic itself as well as during travel there and back again. Risks to the child, accompanying adult and any household members were taken into account. The model also accounted for the household size and age composition in each country, as risk of death from COVID-19 is known to substantially increase with age.

The researchers based their estimates of the number of childhood deaths that could be prevented by routine immunisations on existing health data from each country. They focused on the impact of vaccines for diptheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b and Streptococcus pneumoniae (bacterial causes of pneumonia and meningitis), rotavirus, measles, rubella, meningitis A and yellow fever. Vaccination rates for each country were assumed to be the same as in 2018.

According to the model, continuing with routine immunisation programmes may lead to 8,300 additional deaths across Africa (uncertainty interval 1,300 to 25,000), attributable to SARS-CoV-2 infections associated with children visiting immunisation clinics.

However, suspending such vaccination programmes to avoid excess COVID-19 deaths could lead to 702,000 children across Africa dying from preventable diseases before the age of five (uncertainty interval 635,000 and 782,000), according to the model. The researchers say this scenario assumes no catch-up vaccination campaigns at the end of the COVID-19 risk period and may overestimate the negative impact of suspending vaccination services for a short period of time.

Even in a much more conservative scenario (where suspending vaccination is primarily assumed to increase the chance of a local measles outbreak and children would be protected from other diseases from existing immunity in the population or catch-up immunisation campaigns at the end of the COVID-19 risk period), the number of childhood deaths that could be prevented was still greater than the potential increase in COVID-19 deaths for most countries of Africa.

Dr Tewodaj Mengistu, co-author of the study, from Gavi, the Vaccine Alliance, Switzerland, said: "Routine immunisation programmes are facing enormous disruption across the globe due to this pandemic. Lockdowns make it harder for vaccinators and parents to reach vaccination sessions, health workers are being diverted to COVID-19 response, and misinformation and fear are keeping parents away. This important study shows just how big an impact this could have, risking the resurgence of diseases that vaccines have kept largely at bay." [2]

Findings were similar for all 54 countries of Africa, ranging from between 4 and 124 preventable child deaths in Morocco to between 28 and 598 in Angola, for each excess COVID-19 death. One third of vaccine-preventable deaths would be in Nigeria, Ethiopia, Democratic Republic of Congo and Tanzania, the study found. Around one third of vaccine-preventable deaths would be caused by measles, and another third would be attributable to pertussis, according to the model.

While the study clearly shows the health benefits of vaccination for children, it revealed that the additional risk of COVID-19 infections acquired during visits to the clinic would primarily affect adults from the same household. According to the model, 11% of excess COVID-19 deaths attributable to clinic visits are expected to affect parents or adult carers and 88% are predicted to affect older adults living in the same household as the vaccinated children. The researchers say this highlights the importance of shielding older adults to lower their risk of acquiring COVID-19, while children in their households can benefit from routine vaccinations.

Dr Stefan Flasche, senior author of the study, from the London School of Hygiene & Tropical Medicine, UK, said: "We found that the biggest factors affecting the benefit of maintaining childhood immunisations during the pandemic are the likelihood of transmission of COVID-19 during clinic visits and the number of people encountered at the clinic. This highlights the need for personal protective equipment for clinic staff, the need to implement physical distancing measures and avoid crowded waiting rooms, and the importance of good hygiene practices to reduce virus transmission." [2]

The authors acknowledge that other factors must be considered when making decisions on sustaining routine childhood immunisation programmes during the COVID-19 pandemic. These include vaccine supply chain problems, reallocation of doctors and nurses to other prioritised health services, staff shortages resulting from ill-health or COVID-19 infection, and decreased demand for vaccination caused by fear of contracting COVID-19.

Dr Emily Dansereau, co-author and program officer at the Bill & Melinda Gates Foundation, USA, said: "Across the African continent, many essential health services - from immunization to antenatal care to HIV and TB services - are experiencing significant challenges in the face of COVID-19. To address these new challenges and build resilient health systems, countries are exploring how to rethink health service delivery and are embracing innovative approaches to reach women, children and families with high quality support and care." [2]

A new method for estimating the biological sex of human remains based on reading protein sequences rather than DNA has been used to study an archaeological site in Northern California. The protein-based technique gave superior results to DNA analysis in studying 55 sets of human remains between 300 and 2,300 years old. The work is published July 17 in Scientific Reports.

The method targets amelogenin, a protein found in tooth enamel, said first author Tammy Buonasera, postdoctoral researcher working with Glendon Parker, adjunct associate professor in the Department of Environmental Toxicology at the University of California, Davis. The technique was developed in Parker's laboratory.

Buonasera, Parker, Jelmer Eerkens, professor of anthropology, and colleagues compared three methods for sex determination: the new proteomic method; DNA analysis; and osteology, or analysis of the size, shape and composition of the bones themselves. They applied these methods to remains from two ancestral Ohlone villages near Sunol, California. The site is being excavated by the Far West Anthropological Research Group of Davis in collaboration with the Muwekma Ohlone tribe.

Amelogenin is a protein found in tooth enamel, the hardest and most durable substance in the human body. The gene for amelogenin happens to be located on both the X and Y sex chromosomes, and the amelogenin-Y protein is slightly different from amelogenin-X.

The method works by retrieving a tiny amount of protein from a tooth. All proteins are made up of a chain of amino acids, so the protein is analyzed to give the amino acid sequence, which then defines the protein. Each of the 20 naturally occurring amino acids is specified by a three-letter code in DNA, so it is possible to work backward from the amino acid sequence and figure out the likely DNA code.

Superior to existing methods

The researchers were able to determine the sex of all of the remains using the new protein method and all but five using DNA methods. Results from osteology and proteomics agreed in almost all cases, although examining bones themselves was only effective for about half the skeletons.

The protein method allowed them to estimate sex for children, which is not possible from osteology. It was reliable even when the signal from DNA was weak.

"This is a more sensitive technique for older skeletons where we would expect more DNA degradation," Parker said.

Being able to determine the biological sex of human remains provides a greater window into the persona of each individual. Anthropologists are interested in determining biological sex because sex interacts with health and can have a large impact on how people form an identity and are treated within a society, Eerkens said.

"Almost every human society around the world incorporates sex and gender as a way to classify people, and these can affect your status and who you associate with in society," Eerkens said. While gender and biological sex are not the same thing, they are linked, so the ability to estimate sex gives archaeologists important insight when attempting to understand the cultural aspects of gender, which are not as readily preserved.

For example, in a society based on small villages, people often have to find mates outside their village. Depending on cultural rules, either men or women will leave the village to marry.

Through the investigation of insect surfaces, Penn State researchers have detailed a previously unidentified nanostructure that can be used to engineer stronger, more resilient water repellent coatings.

The results of this research were published today (July 17) in Science Advances.

With an enhanced ability to repel droplets, this design could be applied to personal protective equipment (PPE) to better resist virus-laden particles, such as COVID-19, among other applications.

"For the past few decades, conventionally designed water repellent surfaces have usually been based on plants, like lotus leaves," said Lin Wang, a doctoral student in the Department of Materials Science and Engineering at Penn State and the lead author of the paper.

Classical engineering theories have used this approach to create superhydrophobic, or water repellent, surfaces. Traditionally, they are manufactured with low solid fraction textures, which maintain an extremely thin layer of air above a low density of microscopic, hair-like nanostructures, which the researchers liken to an air hockey table.

"The reasoning is if the droplet or object is floating on top of that air, it won't become stuck to the surface," said Tak-Sing Wong, the Wormley Early Career Professor of Engineering, associate professor of mechanical and biomedical engineering and Wang's adviser.

Since it works effectively, man-made coatings tend to mimic the low density of these nanostructures.

However, this paper details an entirely different approach. When examining surfaces like the eye of a mosquito, body of a springtail or the wing of a cicada under high resolution electron microscopes, Wang found that the nanoscopic hairs on those surfaces are more densely packed, referred to in engineering as high solid fraction textures. Upon further exploration, this significant departure from plants' structure may imbue additional water repelling benefits.

"Imagine if you had a high density of these nanostructures on a surface," Wang said. "It could be possible to maintain the stability of the air layer from higher impact forces."

This could also mean the more densely packed structures may be able to repel liquid that is moving at a higher speed, such as raindrops.

While the design concept is new to humans, the researchers theorize this nanostructure boosts the insect's resiliency in its natural environment.

"For these insect surfaces, repelling water droplets is a matter of life and death. The impact force of raindrops is enough to carry them to the ground and kill them," Wang said. "So, it is really important for them to stay dry, and we figured out how."

With this knowledge gleaned from nature, the researchers hope to apply this design principle to create next generation coatings. By developing a water repellent surface that can withstand faster moving and higher impact droplets, the applications are abundant.

From small, flying robotic vehicles, such as the drones that Amazon hopes to deliver packages with, to commercial airliners, a coating that can emulate these insect surfaces could provide increased efficiency and safety.

However, in light of the COVID-19 pandemic, researchers have since realized this knowledge could have an additional impact on human health.

"We hope, when developed, this coating could be used for PPE. For example, if someone sneezes around a face shield, those are high velocity droplets. With a traditional coating, those particles could stick to the surface of the PPE," Wong said. "However, if the design principles detailed in this paper were adopted successfully, it would have the ability to repel those droplets much better and potentially keep the surface germ-free."

As seen in this work, the Wong Laboratory for Nature Inspired Engineering draws insights from biological phenomena to make humanity's innovations better and more effective.

"While we didn't imagine that application at the beginning of this project, COVID-19 made us think about how we can use this design principle to benefit more people," Wong said. "It's up to us as engineers to take these discoveries and apply them in a meaningful way."

The next step for this work will be developing a large scale, cost effective method that can manufacture a coating to mimic these properties.

"In the past, we didn't have an effective surface that could repel high speed water droplets," Wong said. "But the insects told us how. There are so many examples like this in nature; we just need to be learning from them."